Long calculation of codebook for appearance

[eps696]

During training of the appearance part I've encountered rather long delays (15-20 min) with calculation of the codebook values - obviously because of the amount of frames in the training set.
In the published code the codebook is calculated for every frame (in my case 30 videos for 30004000 frames each). On the contrary, the codebook_a in the published model counts for just 125 arrays, only dozens in length each - despite you mentioned ~2000 videos with hundreds of frames in each in your dataset.
Could you please clarify how should this codebook be properly constructed?